IP filters are used to restrict connections to and from your client. All IP ranges that are entered in the ipfilter.dat file cannot connect to eMule nor can eMule connect to them. This file can be edited via the Edit Button and is saved in eMule's install folder. For more information on filtering IP see the topic IP Filters of this FAQ. eMule has to Reload the ipfilter.dat file before any changes apply.

Filterlevel
Each entry of the ipfilter.dat has an access level assigned. This value describes how trustworthy this entry is. High values (default 128+) are considered secure whereas lower values are to be blocked. The Filterlevel determines the limit of blocking. Each entry in ipfiletr.dat which has an access lower than the set Filterlevel will be denied connection to eMule. The default value should not be changed.

Filter Servers too
The IP-Filter rules are usually only valid for other clients. This option will extend the filtering to servers as well.

Update from URL
Entering a link to a filter file and pressing Load will add the found IPs to eMule's ipfilter.dat. See the IP Filter chapter for links and more information.

See my shared files/directories
This option is used to determine who can view a list of your shared files and directories (it does not affect the sharing of files itself). It offers three settings:

o Everybody
Any client that want to know what files you have shared will be sent an overview of your shared files/directories.

o Friends Only
Only people you have added to your friends list will be able to see your shared files/directories.

o Nobody
eMule will deny all requests for displaying your shared files/directories.

Protocol Obfuscation
Protocol Obfuscation tries to mask your eMule traffic so that it becomes harder to block by your ISP, who may be throttling your connection. See Protocol Obfuscation for more information regarding these settings.

Miscellaneous

Use secure identification
It is recommended to use the secure user identification. For more information on this topic see here.

Run eMule as unprivileged User
This option is only available in the Win NT series (2k, XP, 2003) and allows eMule to profit from the tighter security these systems provide. This option is deprecated on Windows Vista and later.

Most users are logged on to their machine with an Administrator account. This account type allows them and all executed software full control over the system. In this case also all malicious code executed will have its full bad effect.
Running eMule as unprivileged user will create an own user account in the operating system called emule_secure and sets the permissions for full access to the folders it needs (installation folder, temp and incoming folders) for this special user. Otherwise this account is heavily restricted and denies access to other parts of the system. eMule starts itself under this user account making sure that any malicious code which may be injected has no rights on the system, thus not being able to do any harm. This is a preventive measure in case of any vulnerable code is found which could be exploited.

Notes:
o	eMule cares for the file access it needs. Further security can be achieved by deliberately restricting file access to other folder or entire drives. Restricting file access is only possible with NTFS but not with FAT
o	The separate account offers the full possibilities of control mechanisms in modern operating systems like disk quotas etc.
o	A bug in Windows XP prevents any visual styles from working when eMule is run in this mode. The GUI will look like standard Win98. Windows XP SP2 seems to solve this problem.
o	This setting will not provide any anonymity in the network but makes the system eMule runs on more resistant to any possible outside attack.

Enable spam filter for search results
Some malicious servers and Kad nodes return intentional wrong results on searches to promote files of their own. You can mark such results as spam and eMule will try to filter search results which look similar or equal based on heuristic and files you already marked as spam. This option allows you to enable or disable this spam filter.

Warn when opening untrusted files
Downloaded files are marked in the same way as by 'Internet Explorer' which leads to showing a warning message from 'Windows' when executing downloaded files (for Windows XP SP2 or later). This helps to prevent accidental or careless opening of potential malicious files. If you dislike those warning messages, you can disable this function here.